Combination lock construction



Feb. 23,1965 H. c. MILLER ETAL 3,170,316

COMBINATION LOCK CONSTRUCTION Filed Dec. 31, 1962 s Sheets-Sheet 1 INVENTORS 170mg 6.71%; Slat em fi'ksfai Feb. 23, 1965 Filed Dec. 31, 1962 H. c. MILLER s1- m. 3,170,316

COMBINATION LOCK CONSTRUCTION 3 Sheets-Sheet 2 1 INVENTORS kw 5674 4 6. 55 'iewmfieksfa BY A 4? I H. C. MILLER ETAL COMBINATION LOCK CONSTRUCTION Feb. 23, 1965 3 Sheets-Sheet 3 Filed Dec. 51, 1962 mm m m 9 m 5 INVENTORS [Yang ATTORNEYS United States Patent The present invention relates in general to combination locks and more particularly combination locks having means incorporated therein for resisting surreptitious entry techniques of manipulation thereof by unauthorized persons.

Conventional locks of the class known as combination locks usually comprise three tumbler wheels which are loosely journalied in coaxial longitudinally spaced relation for rotation within a lock casing on a tubular arbor or tumbler post projecting inwardly of .the casing from the 7 front wall thereof. The lock dial, which usually has 100 peripheral calibration marks thereon, is affixed to a dial spindle which extends throu'ghthe bore of the tumbler post and has keyed to the inner end thereof a disk-like drive cam which is likewise arranged coaxially with and spaced rearwardly from the tumbler wheels. A drive pin projects forwardly from the drive cam and has a lost motion connection through a conventional fly with the rear most tumbler wheel to drive the tumbler wheel in selected relation to the drive cam. A similar lost motion connection is provided between each of the successive tumblers so that each of the tumblers may be driven upon selected rotation of the drive cam. Each of the tumbler wheels and the drive cam are provided with a peripheral notch or gating at a selected radial position on the cam or tumbler wheels.

A fence lever which ispivotally connected at one end to a reciprocative bolt slidably supported in the lock casing is provided with a depending nose at the opposite end which is designed to ride upon the drive cam periphery and has a bar or fence projecting laterally therefrom in overlying relation with the tumbler peripheries in the tumbler Wheels. The position of the fence in relation to the length of the fence lever nose is usually such that the fence is spaced slightly from the tumbler peripheries when the fence lever nose is riding on the drive cam periphery. V

In such a construction, when the tumbler wheel gatings are out of registry with the fence and the dial is turned to the proper position to dispose the drive cam gating below the fence lever nose, the fence lever nose will drop slightly into the drive cam gating until the fence bears upon the tumbler peripheries. The rotation of the dial through small arcs in opposite directions from this position will bring the opposite surfaces of the drive cam gating into contact with the fence lever nose. The points at which the fence lever nose contacts these opposite surfaces at the entrance to the drive cam gating are known as the left and right contact points of the fence lever and may be detected by coordination of the senses of touch (and sight by the person manipulating the dial. A variation in the relation and feel of these contact points occurs when one of the tumbler gatings is positioned beneath the fence, which is distinguishable from the relation and feel of these'contact points when all of the tumoler gatings are out of registry with the fence. Because of the fact that the drive cam can be rotated through a suflicient are when the fence is in contact with the tumbler peripheries to reveal the contact points of the fence lever nose, the location of the three tumbler wheel gatings can be determined by unauthorized persons by following a now well known lock manipulation procedure.

Various modifications in combination lock structure 3,170,315 Patented Feb. 23, 1965 have heretofore been resorted to to defeat detection of the lock combination in this manner. Among these is the lock structure disclosed in prior Patents Nos. 2,575,- 674 and 2,807,954 granted to Harry C. Miller wherein a shielding slide is mounted on the rear face of the drive cam and has a curved end portion conforming to the curvature of the drive earn periphery which normally overlaps the drive cam gating and forms a smooth continuation of the drive cam periphery to support the fence lever nose when the drive cam gating is in registry with the fence lever nose. An inner spindle extends through the dial spindle and is coupled at its inner end to the shielding slide and at its outer end to a knob which is in exposed condition, whereby upon rotation of the knob.

and inner spindle, the slide may be shifted radially of the drive cam to expose the drive cam gating for reception of the fence lever nose. When the shielding slide is in projected position exposing the drive cam gating to entry of the fence lever nose, stopmembers on the lock casing are disposed in the path of movement of a portion of the slide to limit rotation of the drive cam to an extent which will prevent detection of contact points for the fence lever nose.

it has been determined, however, that the security of this look may be adversely affected in time if the portion of the shielding slide which is projected beyond the drive cam periphery becomes worn, as by abrasion against adjacent surfaces of the lock casing. It is possible that the projected end surface of the shielding slide may become worn to a depth equal to the spacing of the fence from the tumbler wheel peripheries when the fence lever nose engages the drive cam periphery. In such a case, the slide may be only partially projected from the position wherein it shields the drive cam gating to lower the fence into contact with the tumbler peripheries and lower the fence lever noseinto at least the entrance to the drive cam gating without projecting the slide sufiiciently to permit the stop members to limit rotation of the drive cam.

persons.

Another object of the present invention is the provision of a novel combination lock. mechanism of the type having a reciprocative shielding slide carried by the drive cam for normally shielding the drive cam gating against entry of the fence lever nose therein when the lock is conditioned for tumbler'adjusting rotation. and an adjusting member for causing the slide to assume a gate exposing displaced position, wherein means directly actuated by the slide adjusting member is provided intermediate the adjusting member and the slide to permit movement of the slide to displaced position only when movement of the adjusting member is adequate tofullythrow the slide to said position.

Another object of the present invention is the provision of a novel combination lock mechanism of the type having a reciprocative shielding slide carried by the drive cam for normally shielding the drive cam gating against entry of the fence lever nose therein when the lock is conditioned for tumbler adjusting rotation and an adjusting member for causing the slide to assume a gate exposing displaced position, wherein a second reciprocative slide carried by the driving cam is directly actuated by the adjusting member and resilient means intercouples the second slide to the shielding slide in a manner to cause delayed action projection of the shielding slide to fully displaced position upon a selected degree of movement of the adjusting member and to prevent any movement of the shielding slide upon less than said selected degree of movement of the adjusting member.

Another object of the present invention is the provision in a combination lock mechanism of the type having a shielding slide member normally positioned to prevent entry of the fence lever nose into the drive cam gating during adjustment of the drive cam and tumblers, means for shifting said shielding member between shielding and non-shielding positions in response to movement of an adjusting member, and means for imposing a selected restraint on rotation of the drive cam when the shielding slide member is shifted fully to non-shielding position of an auxiliary slide member on the drive cam associated with said adjusting member and spring means intercoupled between said slide members which is deformed and displaced during initial movement of said adjusting member and shifts said shielding member fully to nonshielding positions when the adjusting member reaches a selected position.

Other objects, advantages and capabilities of the present invention will become apparent from the following detail description taken in conjunction with the accompanying drawing showing two preferred embodiments of the invention.

In the drawings:

FIGURE 1 is a vertical section view of one embodiment of a combination lock made in accordance with the present invention, taken along the line 11 of FIG- URE 3;

FIGURE 2 is a rear elevation of the combination lock with the rear cover removed;

FIGURE 3 is a fragmentary rear elevation similar to FIGURE 2 showing the shielding slide in gate shielding position;

FIGURE 4 is a front elevation of the rear cover of the lock casing;

FIGURE 5 is a horizontal section view taken along the line 55 of FIGURE 3;

FIGURE 6 is a fragmentary vertical section view of a modified driving cam assembly embodying the present invention, for use in combination locks taken along the line 6-6 of FIGURE 8;

FIGURE 7 is a rear elevation view of the driving cam assembly shown in FIGURE 6 showing the slides in gate exposing position;

FIGURE 8 is a fragmentary rear elevation similar to FIGURE 7 showing the slides in gate shielding position; and

FIGURE 9 is a horizontal section view taken along the line 9-9 of FIGURE 8.

Referring to the drawings, wherein like reference characters designate corresponding parts throughout the several figures, and particularly to FIGURES 1 to 5, inclusive, showing one preferred embodiment of the invention, there is illustrated a combination lock, generally indicated by the reference character 10, which is of the general type disclosed in the prior Patents Nos. 2,575,674 and 2,807,954 issued to Harry C. Miller. The combination lock comprises a substantially rectangular lock casing 10 having a hollow boss 11 projecting in opposite directions from the front wall thereof and through a door 12. Secured to the threaded outer end of the hollow boss 11 is a conventional escutcheon plate 13.

Rotatably supported within the hollow boss 11 is an axially bored drive spindle 14 threaded at its outermost end to a dial knob 15 having aflixed thereto a conventional dial 16 supported to rotate within the recess of the escutcheon plate 13. The inner end of the drive spindle 14 is threaded to receive an internally threaded portion of a tubular boss 17 projecting from a driving cam 18, the driving cam being keyed to the driving spindle 14 by means of a suitable spline.

A plurality of tumblers, generally indicated by the reference characters 19, 20 and 21 are supported to rotate freely upon the portion of the hollow boss projecting within the lock casing 10, each of the tumblers being of the conventional type designed to be changed by means of a combination resetting key to vary the combination of the lock, and to this end comprising an inner hub on each of which are supported a pair of annular disks hav ing a tumbler gate or recess 22 therein. The outer annular disks are selectively locked against rotation relative to their supporting hubs by means of conventional locking arms carried by the annular disks and engaging peripheral serrations or teeth on the hubs to hold the annular disks in fixed position.

Conventional flys 23 consisting of annular rings hav ing an outwardly radiating projection thereon are provided between the outermost and intermediate tumblers 21 and 2t) and between the intermediate and innermost tumblers 2t) and 19 to rotate in annular recesses provided in the adjacent faces of the inner hubs of the tumblers 21 and 20, The radial projections of the flys engage stops on the adjacent tumblers to provide a lost motion driving connection between the tumblers operatively associated with each fly. The innermost tumbler 19 is provided with a special fly 24 having an annular ring to surround and ride freely on the hollow boss 11 and an outwardly radiating projection terminating in a triangular tip having inclined converging faces producing a cam surface, the faces being inclined, in the preferred embodiment, at external angles of 130 degrees each with the medial radial plane of the projection.

The lock is provided with a bolt 25 which is adapted to slide in a suitable guideway formed in one wall of the casing 10, the bolt 25' being operated by a fence lever 26 pivotally attached thereto by means of a screw 27. The fence lever 26 is continuously resiliently urged toward the tumblers by means of a suitable spring 28 and is provided with a laterally projecting arm 29, commonly referred to as a fence, which projects along an axis parallel to the axis of the drive spindle 14 and overlies the peripheries of all the tumblers 19, 2t) and 21. The fence 29 is adapted to be received in the gates 22 of the tumblers when the tumbler gates are disposed in registry upon operation of the dial knob 15 to establish the combination. The downward rotation of the fence lever 26 when the fence enters the gates permits the shoulder 30 on the free end of the fence lever 26 to fall free of the depending boss 31 on the top wall of the lock casing 10 and permit the fence lever to be shifted laterally beyond the boss 31 to withdraw the bolt 25 from its projected position.

The driving cam 18 is provided with a recessed peripheral portion 32 extending over approximately 75 to degrees of the circumference of the driving cam, in the center of which recessed portion is a driving cam gate 33 adapted to receive the nose 34 of the fence lever 26, As will be observed from the illustration of the driving cam 18 in FIGURE 3, the driving cam gate 33 has a pair of diverging walls, one forming an inclined slightly convex wall for controlling the movement of the fence lever nose 34 into the driving cam gate and therefore the speed of approach of the fence 29 toward the tumbler peripheries,. and the other wall forming a shoulder for cooperating with a complementary shoulder on the fence lever nose 34- by which the fence lever 26 is shifted to retract the bolt 25 7 upon rotation of the driving cam in a counterclockwise. direction as viewed in FIGURE 2.

Projecting from opposite portions of the rearmost faceof the driving cam 18 are a pair of guide blocks 35 havingv a forward pair of guide grooves 36 formed in the adja-- cent surfaces thereof to support a shielding slide 37 for rectilinear movement along a diametrical axis of the driving cam 18. The length of the slide 37 corresponds to the maximum diameter of the driving cam 18 and is provided with opposite ends 38 and 39 which are arcuately curved to correspond with the projected circular path of the periphery of the driving cam 18 so as to present, when the slide 37 is in the position illustrated in FIGURE 3,,

an uninterrupted driving cam periphery to thejnose 34 i 1 of the fence lever 26.

The slide 37 ,is provided at its lower end 39 with a driving pin 4% projecting forwardly of the slide 317 which has a triangular tip forming inclined cam faces adapted to Cooperate with thecam faces'on the projection of the rearmost fly 24 and impart rotation to the fly 24 upon rotation of the driving cam 18 when the slide 37 is dis posed in shielding position. The shielding slide 37 has a central slot 41 elongated along anaxis paralleling the straight sides of the slide 37, an anchoring stud 42 projecting rearwardly therefrom, and a pair of vertically. spaced, rearwardly facing recesses $3, 44 of rectangular plan and concave cylindrical profile provided along one lateral edge an axis paralleling the axis of reciprocative movement of the shielding slide. The actuating slide 46 has an arcuate lower end 47 having a curvature corresponding to that of the end 3910f shielding slide 37, and a straight upper end 48 from which a rearwardly curving rigid finger 49 projects.

A central elongated slot Stl corresponds ap slide 46 to receive the check ball 58 and accurately locate the slides 37 and 46 relative to each other at the normal or shielding position. Similarly, a circular recess 6t] is provided in the actuating slide 46 below the recess 59 which cooperates with recess 43 to receive the ball 58 and accurately locate the two slides at the projected 'or nonshielding position. The ball 58 is restrained against displacement relative to the driving cam 18 by a suitable recess 61 in the side of one of the guide blocks.35.

The rear cover 62 of the lock casing, illustrated in FEGURE 5, is provided with a circular recess 63 for accommodating the driving cam 18','which recess is joined along a circumferential portion thereof by an arcuate extension 6 4 to receive a portion of the actuating slide 46 prox mately to the slot 41 and opens through the lower end of the actuating slide 46, and a truncated triangular opening 51 is located eccentrically of the center of the actuating slide 46 to receive a substantially triangular nose 52 of a slide actuating cam or tang member 53. The

or short coil spring having diverging legs rotatably mounted on the studs 56 and 42 on the slides 45 and 37 respectively. The .stud 56 is located inwardly of and when the same is projected to non-shielding position and accommodate limited arcuate movement of the driving tion, the outer' portion of the radial guideway groove 65 being joined by an arcuate groove portion 65 concentric with the axis of the driving cam 18 through which the finger 4% moves when the driving cam 18 is rotated through the limits necessary to retract the bolt. 7

combination lockof the above-described construction is manipulated in the conventional'manner to position the tumbler gates in registry with each other and in alignment with the fence 29 by rotating the dial knob 15 and dial 16 three complete revolutions in a counterclockwise direction to bring a preselected dial marking in alignment with the index mark on the escutcheon plate 13, then two below the stud 42 when the slides 46 and 37 are both in J normal or shielding position as illustrated in FIGURE 3,

causing the coil or apex portion 57' of the spring 57 to be directed to the right in a slightly upwardly inclining direction as viewed in FIGURES. As the auxiliary knob 55 and inner spindle 54 are rotated' in a counterclockwise direction as viewed in FIGURE 3, the nose 52 of the tang 53 acting on the walls. bounding the slot 51 cause the actuating slide 46 to move upwardly along a diameter of a downward component, and the stored energy is released against the stud 42' to drive the shielding'slide 37 downwardly to projected or non-shielding position exposing the driving cam gate 33 to receive the fence lever nose 34, Since thereis no force component of the spring 57 acting on the stud 42 in'a downward direction until the stud 56 passes just above the stud 42, projection of the shielding slide 37 to non-shielding position is prevented until sufficient energy is stored in the spring 57 to insure full pro:

jection of the shieldingslide to its limit position. Av

check such as a ball 58 is seated in the lower ball check recess 44 of shielding slide 37 when the latter is in normal or shielding position, and a cooperating upper recess 59 of substantially semi-circular plan and rectangular profile isprovidedin the corresponding lateral edgeof actuating complete turns in a clockwise direction to bring another dial marking into alignment with the fixed index mark, and then another complete revolution in a counterclockwise direction to align the third dial number with the index mark. During this manipulation of the dial knob and dial, the shielding slide 37 is in the position illustrated in FIGURE 3 of the drawing wherein the arcuate ends 38, 3% of the slide complete the circular periphery of the brin the zero mark into alignment with a fixed index mark onthe escutcheon plate 13 In thisposition the rearwardly projecting finger 49 on the rear actuating slide 7 46 is aligned radially with the radial guideway groove 65 in the rear cover 62, and the driving cam gate 33 is disposed immediately below the fence lever nosed' l. The

auxiliary knob 55 is then rotated through a selected range,

' rotating the inner spindle 54 and tang 53 in an appropriate direction to shift the actuating slide'46 upwardly along a rectilinear inclined path toward the position "illustrated in FEQUR'E 2. When the anchoring stud 56 on the actuat ng slide 46 passes above the anchoring stud 4201i the shielding slide37 as previously described, the angular position of the spring 57 which 'has been highly tensioned during the relative approaching movement of the studs is shifted so as to exert adownward force on the-stud '42 a and shielding slide 37 thestored energy in the spring 57 being sufficient to fully project the shielding slide '37. to the nonshielding position illustrated in FIGURE '2. If

the tumbler gates 22 were aligned in position to receive in a counterclockwise direction as viewed in FIGURE 2 through a suflicient angle to retract the bolt;

, To reclose the lock, the operator need merely rotate the dial in the reverse direction to bring the finger 49 on the actuating slide 46 into alignment with the radial guideway groove 65 andthen rotate the auxiliary knob 55 in the reverse direction, which rotates the tang 53 and returns the actuating slide 46 to its normal position, the spring 57 being shifted in a reverse relation by the movement of the stud 56 relative to the stud 42 to return the shielding slide 37 to its normal position.

- FIGURES 6 to 9 illustrate a modified drive cam assembly which has a similar principle of operation to the drive cam assembly of the preceding embodiment. The modified drive cam assembly of FIGURES 6 to 9, indicated generally by the reference character 100 is adapted to be used with other lock components similar in construction to those disclosed in the preceding embodiment, including the periphery gated tumbler wheels 19, and 21 having lost motion flys 23 between the rearmost and intermediate tumbler wheels 21 and 20 and between the intermediate and forwardmost tumbler wheels 20 and 19, the special fly 24 immediately rearwardly of the rearmost tumbler wheel 21, the bolt 25 and fence lever 26 pivotally connected thereto having a fence 29 normally overlying the tumbler wheel peripheries, the dial 15 having a dial knob 15 thereon and a rearwardly, axially bored drive spindle 14, and the inner spindle 54 extending through the bore of the drive spindle 14 and terminating forwardly in an auxiliary knob 55. Therefore, illustration of these conventional components in the drawings and specific description of this conventional portion of the lock construction is unnecessary to an understanding of the modified embodiment.

The drive earn 101 of the modified drive cam assembly 100 is generally similar to the drive cam 18 and is provided with a peripheral recess 102 having a gate 103 in a portion thereof adapted to receive the nose 34 of the fence lever 26 and coact therewith to withdraw the bolt 25 upon suitable rotation of the driving cam 101. The driving cam 101 has a forwardly projecting boss 104 which is bored and internally threaded, to be threaded onto the rear end of the drive spindle 14 and be suitably keyed thereto by a spline in the conventional manner. A pair of rearwardly projecting guide blocks 105, 106 are provided on the drive cam 101 in laterally spaced relation similar to the guide blocks of the first described embodiment, except that the guide blocks 105, 106 have only a single pair of guide grooves 107 in the adjacent faces thereof to receive and slidably support the straight lateral edges of a'shielding slide 108. The shielding slide 108 has arcuately curved upper and lower ends 109, 110 which correspond to and normally form continuations of the circular periphery of the driving earn 101. A rectangular opening 111 is provided in the shielding slide 108, the lateral edges 112, 113 of the opening 111 being straight and being located outwardly of the edges of the lips 114 of the guide blocks 105, 106 rearwardly bounding the guide grooves 107. These lateral edges 112, 113 of the opening 111 in the shielding slide 108 form guide surfaces for the lateral edges of the rectangular body portion 115 of an auxiliary slide 116 disposed for sliding movement within the opening 111. Projecting rearwardly from the rectangular body portion 115 of the auxiliary slide 116 is a block portion 117 which is slightly narrower than the distance between the adjacent edges of the lips 114 of guide blocks 105, 106, the opposite sides of the rearwardly projecting block portion 117 having diagonal notches 118 therein to receive the ends of generally horseshoe shaped springs 119 whose other ends are rotatably anchored to the guide blocks 105, 106 by anchoring screws 120.. The forwardly facing surface portion of the body portion 115 of auxiliaryslide 116 is provided with a recessed trough 121 extending from the top to the bottom edges of the body portion 115 to accommodate a tang 122 fixed on the rearmost end of the inner spindle 54, the recessed trough 121 having a lateral extension 123 bounded by upper and lower shoulders 124, 125 to be engaged by the tang 122 upon rotation of the inner spindle 54 for shifting the auxiliary slide 116 betwen the normal position illustrated in FIGURE 8 and the displaced or non-shielding position of FIGURE 7. The upper and lower horizontal edges 126 and 127 of the opening 111 in the shielding slide 108 are so spaced that the lower horizontal surface of the body portion 115 of auxiliary slide 116 abuts the lower edge 127 of the opening 111 in shielding slide 108 during downward travel of the auxiliary slide 116 to carry the shielding slide 108 downwardly in the guideway provided therefor to the position illustrated in FIGURE 7 wherein the driving cam gate 103 is disposed to receive the fence lever nose 34. During the first portion of travel of the auxiliary slide 116 from the normal position illustrated in FIGURE 8 to a position wherein the ends of the springs 119 seated in the notches 118 are aligned with the anchoring screws 120, the springs 119 will be progressively compressed, effecting a storage of energy therein. When the ends of the springs 119 riding in the notches 118 then pass slightly below the anchoring screws 120, the energy stored in the springs is then free to propel the auxiliary slide 116 further downwardly until the springs 119 resume their normal condition, this effecting the desired stroke of the auxiliary slide 116 to project the shielding slide 100 to non-shielding position in the latter phase or portion of the stroke of auxiliary slide 116. The return of the auxiliary slide 116 and shielding slide 108 to normal position may then be effected by reverse rotation of the inner spindle 54 and tang 122. It will be appreciated that suitable ball check means may be provided in adjacent portions of a side of the shielding slide 108 and one of the guide grooves 107 therefore to resiliently or frictionally restrain and locate the shielding slide 108 at the two limit positions therefor, similar to that provided in the first above-described embodiment or in the earlier U.S. Patent No. 2,900,813 granted to Harry C. Miller, or a springpressed ball such as shown at 128 may project from one of the guide blocks 105, 106 into a recess 129 in the adjacent edge of the shielding'slide 108, whose upper and lower ends serve as limit stops and which has a slightly raised section between the two limit positions and resiliently restrain the shielding slide at the limit positions. The drive pin 130 for the tumbler wheels may be fixed on the lower end portion of the shielding slide 108 and include a rearwardly projecting portion 130' extending beyond the rear surface of the block 117 on activating slide 116 to project into a circular recess in the rear cover of the lock casing to block outward radial movement of the pin 130 and shielding slide at all but one angular position of the driving cam. A radial extension groove having an arcuate portion at the outer end thereof may join the circular recess at the selected angular position to accomodate radial and limited circumferential movement of the shielding slide 100 in a manner analogous to the extension grooves 65, 66 of the first embodiment.

While but two preferred examples of the present invention have been particularly shown and described, it is apparent that various modifications may be made therein within the spirit and scope of the invention, and it is desired, therefore, that only such limitations be placed on the invention as are imposed by the prior art and set forth in the appended'claims.

What is claimed is:

1. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler Wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said shielding position to a non-shielding position relative to the driving cam gate, a movable actuatingmember carried on said driving cam, manipulating means coupled to said actuating member for moving the latter relative to said shielding slide over a preselected range of movement, and spring means coupled to saidactuating member and to said shielding slide to be actuated by movement of the actuating member to store up energy during movement of the actuating member toward a selected intermediate position in said range of movement and be shifted to a direction upon passage of said intermediate position to expend the stored up energy on said shielding slide to drive the latter fully to said non-shielding position.

2. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a

rotatable driving cam for adjusting said tumbler wheels, a

bolt, a fence lever pivotally connected to said bolt having anose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said driving cam gate against entry of the fence lever nose therein including areciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, a radially movable actuating slide carried on said driving cam, manipulating means coupled to said actuating slide for moving the latter relative to said shielding slide over a preselected range of movement, and

shielding slide to be actuated by movement of the actuating slideto undergo compression during movement thereof toward a selected intermediate position in said range of movement and be shifted to a direction upon passage of said intermediate position to expend the return force of the spring means on said shielding slide to drive the latter fully to said non-shielding position.

3. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said driving cam gate against entry of the fence lever nose therein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, a radially movable actuating slide carried on said driving cam, manipulating means coupled to said actuating slide for moving the latter relative to said shielding slide over a preselected range of movement, spring means coupled to said actuating slide and tosaid shielding slide to be actuated by movement of the actuating slide to undergo compression during movement thereof toward a selected intermediate position in said range of movement and be shifted to a direction upon passage of'said intermediate position to expend the return force of the spring means to drive said shielding slide fully to said non-shielding position, a rigid finger projecting rear wardly from said actuating slide, and a casing for said lock having a guide groove therein for receiving said finger and accommodating radial movement of said actuating slide at only one selected angular position of said driving cam and limited rotary movement of the driving cam ,spring means coupled to said actuating slide and to said i i p 10 when the actuating slide is displaced fully from its normal position. l

4. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler Wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding'means to selectively shield said driving cam gate against entry of the fence lever nose respectively located to effect compression of said spring member during movement of said actuating slide toward a selected intermediate position in said range of movement and shift said spring member upon passage of said intermediate position to a direction whereby the return force of the spring member drives said shielding member fully to non-shielding position.

5. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler Wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to seleotively'shield said driving cam gate against entry of the fence lever nose therein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, a reciprocative actuating slide supported on said driving cam for radial movement in a plane passage of said intermediate position to a direction whereby the return force of the spring member drives said shielding member fully to non-shielding position.

6. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter, are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said driving cam gate against entry of the fence lever nose therein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, a reoiprocative actuating slide sup- 3 l ported on said driving cam for radial movement in a plane paralleling and spaced rearwardly from said shielding slide, manipulating means coupled to said actuating slide for moving the same relative to the driving cam over a preselected range of movement paralleling the axis of movement of said shielding slide, a spring member having opposite ends anchored to said shielding slide and actuating slide respectively at laterally offset points relative to said axis of movement located to effect compression of said spring member during movement of said actuating slide toward a selected intermediate position in said range of movement and shift said spring member upon passage of said intermediate position to a direction whereby the return force of the spring member drives said shielding member fully to non-shielding position.

7. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said driving cam gate against entry of the fence lever nosetherein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, a reciprocative actuating slide supported on said driving cam for radial movement, manipulating means coupled to said actuating slide for moving the same relative to the driving cam over a preselected range of movement paralleling the axis of movement of said shielding slide, a spring member having opposite ends anchored to said shielding slide and actuating slide respectively at laterally olfset points relative to said axis of movement located to effect compression of said spring member during movement of said actuating slide toward a selected intermediate position in said range of movement and shift said spring member upon passage of said intermediate position to a direction whereby the return force of the spring member drives said shielding member fully to non-shielding position, a rigid finger projecting rearwardly from said actuating slide, and a casing for said lock having a guide groove therein for receiving said finger and accommodating radial movement of said actuating slide at only one selected angular position of said driving cam and limited rotary movement of the driving cam when the actuating slide is displaced fully from its normal position.

8. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler Wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said driving cam gate against entry of the fence lever nose therein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, a reciprocative actuating slide supported on said shielding slide for radial movement axially aligned with the axis of movement of said shielding slide, manipulating means coupled to said actuating slide for moving the same relative to said driving cam over a preselected range of movement sufficient to fully displace said shielding slide to non-shielding position, said shielding slide having stop surfaces spaced to accommodate a limited degree of relative movement of said actuating slide therebetween and engageable by said actuating slide to shift the shielding slide during a terminal part of said range of movement, and spring means anchored at points on said driving cam having free ends coupled to said actuating slide positioned to be compressed upon movement of said actuating slide over most of said limited degree of relative movement and angularly shifted through over-center positions relative to the anchored points to propel said actuating slide by spring return force through the terminal part of said range of movement fully displacing said shielding slide to nonshielding position. i

9. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the peripheries of said tumbler wheels, said driving cam having a peripheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said driving cam gate against entry of the fence lever nose therein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, said shielding slide having a guide opening therein, a reciprocative actuating slide supported on said shielding slide in said guide opening therein for radial movement axially aligned with the axis of move-v ment of said shielding slide, manipulating means coupled to said actuating slide for moving the same relative to said driving cam over a preselected range of movement sufficient to fully displace said shielding slide to nonshielding position, said shielding slide having stop surfaces at opposite ends of said guide opening spaced to accommodate a limited degree of relative movement of said actuating slide therebetween and engageable by said actuating slide to shift the shielding slide during a terrnrnal part of said range of movement, and spring means anchored at points on said driving cam having free ends coupled to said actuating slide positioned to be compressed upon movement of said actuating slide over most of said limited degree of relative movement and angularly shifted through over-center positions relative to the anchored points to propel said actuating slide by spring return force through the terminal part of said range of movement fully displacing said shielding slide to non-shielding position. I 10. In a combination lock having a plurality of selectively adjustable, peripherally recessed tumbler wheels, a rotatable driving cam for adjusting said tumbler wheels, a bolt, a fence lever pivotally connected to said bolt having a nose for engaging the periphery of said driving cam and a radially extending fence transversely overlying the pelIPhBIlCS Of said tumbler wheels, said driving cam having aperipheral gate for receiving said fence lever nose to permit said fence to enter the tumbler recesses when the latter are adjusted in registry therewith; the improvement comprising shielding means to selectively shield said drivng cam gate against entry of the fence lever nose therein including a reciprocative shielding slide supported on said driving cam for radial movement from a normal shielding position to a non-shielding position relative to the driving cam gate, said shielding slide having a guide opening therein, a reciprocative actuating slide supported on said shielding slide in said guide opening therein for radial movement axially aligned with the axis of movement of said shielding slide, manipulating means coupled to said actuating slide for moving the same relative to said driving cam over a preselected range of movement suflicient to fully displace said shielding slide to non-shielding position, said shielding slide having stop surfaces at opposite ends of said guide opening spaced to accommodate a limited movement, said actuating slide having a block portion projecting rearwardly of said shielding slide having laterally opening notches therein, and spring means anchored at points on said driving cam in laterally flanking relation to said block portion having'free ends seated in the notches of said block portion positioned to be compressed-upon movement of said actuating slide over most of said limited degree of relative movement and angularly shifted through over-center positions relative to the anchored points to propel said actuating slide by spring return force through the terminal part of said range of movement fully displacing said shielding slide to non-shielding position.

'11. In acombination lock, the combination defined in claim 1 including means for releasably restraining said shielding slide against movement from said normal shielding position during said movement of said actuating member toward the selected intermediate position and responsive to a superior force exerted against said shielding slide toward said non-shielding position by said spring means to toward said non-shielding position by said spring means to release the shielding slide for movement to said non- V shielding position.

12. In a combination lock, the combination defined in release the shielding slide for movement to said non-shielding position.

'13. Ina combination lock, the combination definedin claim 6 including spring check means for releasably restraining said shielding slide against movement from said normal shielding position during said movement of said actuating member toward the selected intermediate position and responsive to a superior force exerted against said shielding slide toward said non-shielding position by said spring means to release the shielding slide for movement to said non-shielding position. a

14. In a combination lock, the combination defined in claim 8 including spring check means for releasably restraining said shielding slide. against movement from said normal shielding position during saidmovement of said actuating member toward the selected intermediate position and responsive to a superior force exerted against said shielding slide toward said non-shielding position by said spring means to release the shielding slide for movement to said non-shielding position.

References Cited by the Examiner UNITED STATES PATENTS 2,575,674 11/51 Miller 70-284 2,807,954 10/57 Miller 70 s33 2,900,813 5/59 Miller 70- 333 ALBERT H. KAMPE, Primary Examiner 

1. IN A COMBINATION LOCK HAVING A PLURALITY OF SELECTIVELY ADJUSTABLE, PERIPHERALLY RECESSED TUMBLER WHEELS, A ROTATABLE DRIVING CAM FOR ADJUSTING SAID TUMBLER WHEELS, A BOLT, A FENCE LEVER PIVOTALLY CONNECTED TO SAID BOLT HAVING A NOSE FOR ENGAGING THE PERIPHERY OF SAID DRIVING CAM AND A RADIALLY EXTENDING FENCE TRANSVERSELY OVERLYING THE PERIPHERIES OF SAID TUMBLER WHEELS, SAID DRIVING CAM HAVING A PERIPHERAL GATE FOR RECEIVING SAID FENCE LEVER NOSE TO PERMIT SAID FENCE TO ENTER THE TUMBLER RECESSES WHEN THE LATTER ARE ADJUSTED IN REGISTRY THEREWITH; THE IMPROVEMENT COMPRISING SHIELDING MEANS TO SELECTIVELY SHIELD SAID DRIVING CAM GATE AGAINST ENTRY OF THE FENCE LEVER NOSE THEREIN INCLUDING A RECIPROCATIVE SHIELDING SLIDE SUPPORTED ON SAID DRIVING CAM FOR RADIAL MOVEMENT FROM A NORMAL SHIELDING POSITION TO A NON-SHIELDING POSITION RELATIVE TO THE DRIVING CAM GATE, A MOVABLE ACTUATING MEMBER CARRIED ON SAID DRIVING CAM, MANIPULATING MEANS COUPLED TO SAID ACUTATING MEMBER FOR MOVING THE LATTER RELATIVE TO SAID SHIELDING SLIDE OVER A PRESELECTED RANGE OF MOVEMENT, AND SPRING MEANS COUPLED TO SAID ACTUATING MEMBER AND TO SAID SHIELDING SLIDE TO BE ACTUATED BY MOVEMENT OF THE ACTUATING MEMBER TO STORE UP ENERGY DURING MOVEMENT OF THE ACTUATING MEMBER TOWARD A SELECTED INTERMEDIATE POSITION IN SAID RANGE OF MOVEMENT AND BE SHIFTED TO A DIRECTION UPON PASSAGE OF SAID SHIELDING SLIDE TO DRIVE THE THE STORED UP ENERGY ON SAID SHIELDING SLIDE TO DRIVE THE LATTER FULLY TO SAID NON-SHIELDING POSITION. 